The invention relates to a device for the detachable connection of a vehicle seat that guarantees a secure locking and when necessary a simple unlocking of the vehicle seat.
From German Patent DE A1 44 04 935 a device is known for connecting a vehicle seat to a vehicle floor which uses for locking the seat to a bolt of the front bearing block a double-armed locking lever, and for locking with the bolt of the rear bearing block a hook which is open in the travel direction. The double-armed locking lever is held in the unlocked position by a spring in a stop wherein the free end of the one arm is associated with a stop fixed on the vehicle floor. After inserting the fixing point of the vehicle seat into the floor-side bearing blocks, the seat is pushed forwards to produce the keyed locking connection whereby the rear fixing bolt enters between the flanks of the rear fixing hook. At the same time the seat slides inclined down and forwards on a guide slide of a support plate which also supports the double-armed locking lever. This produces an engagement of the floor-side support with the one arm of the locking lever and its swivelling in the direction of the locking position. After reaching a certain swivel angle, the active direction of the spring on the locking element changes round so that this locking element is automatically drawn into the locking position.
The described device does indeed allow a single locking and unlocking of a vehicle seat but it does have the drawback however that the rear locking point is designed in the form of an open hook and cannot absorb forces against the travel direction. In the event of a rear impact crash the front locking point would have to divert the entire energy connected therewith. Furthermore it cannot be completely ruled out that the seat is locked in the front bearing block while the rear fastening hook does not enclose the fixing bolt but stands up on same. Such an unsecured seat gives rise to a considerable risk of accident and injury.
German Patent DE 44 08 696 C1 describes a device for connecting a longitudinal support of a vehicle seat with the vehicle structure whereby a fixing claw which is open to the back engages round a fixing bolt fixed on the body so that even crash forces produced at the rear can be absorbed. After the rear fixing area has been brought into positive engagement the front fixing claw can be lowered onto the associated fastening bolt and can be secured by means of a locking element.
A disadvantage here however is that a locking of the front seat area can also then take place when the rear fixing area rests on the fixing bolt on the bodywork side, i.e. when no rear locking exists. Such a faulty mounting can, during operation of the vehicle, more particularly with severe negative accelerations, lead to the seat folding forwards and thus to severe injury to the user.
From U.S. Pat. No. 5,282,662 a device is known for detachably connecting a vehicle seat to the vehicle floor. The device has two front and two rear slide guides. Fixing bolts are located in engagement with each engagement of the front and rear slide guide. The vehicle seat is fixed or locked on the fixing bolts by fixing hooks. Furthermore the known device has a rod which connects a support foot with a leg of the vehicle seat. In order to remove the vehicle seat it is folded into a vertical position whereby the rear slide guides (or legs of the seat) fold together as a result of their connection with the foot through the rod.
Even with this known device a locking of the front seat area can take place even if the rear fixing area is not properly locked.